One state-of-the-art cryogenic surgical instrument is known to comprise a body and a working portion, which consists of a heat-exchanger and a blade. The body includes inlet and outlet pipings for the refrigerant to pass, while the heat-exchanger has a blade heating coil, said blade being made of a Pt-Ir alloy.
Such an instrument, however, features a low refrigerating capacity of its heat-exchanger, while a low rate of biologic tissue dissection with such an instrument is due to a consecutive connection of cold and heat to the working portion, i.e., the heat-exchanger and the heating coil operate alternatively. Thus, a hemostatic effect attainable by said instrument is also inadequate (cf. a prospectus Lumberoupoulos, 1967 , the Federal Republic of Germany).
One more prior-art cryogenic scalpel is known to comprise a hollow housing and a working portion connected thereto and incorporating a heat-exchanger and a cutting blade. The heat-exchanger pipes run through the interior space of the housing, while the scalpel has an electric heater to heat the blade (GB, A, 1,247,301).
The aforesaid scalpel operates on the principle of an alternative feeding of cold and heat, the former being generated by the heat-exchanger through which a refrigerant (i.e., a gas-liquid mixture) is free to circulate, while heat is generated by the electric heater. The cold thus generated is used for establishing hemostasis at the instant when biologic tissues are cut-through, with the result that the blade sticks to the tissues being dissected, which is counteracted by thawing the blade by heating.
Such a process features but a low dissection rate due to obligatory alternation of cold and heat and leads to a high degree of traumatization on account of tissue sticking to the blade. The scalpel has a low refrigerating capacity due to obligatory alternation of cooling and heating of the blade with the resultant inadequate hemostatic effect from the application of such a scalpel.
Besides, the scalpel is bulky and inconvenient in handling.